1. Field of the Invention
The present invention relates to a modular prefabricated element used in building construction, particularly used for making floors and related slabs with cast concrete interspaces.
2. State of the Prior Art
It has been known for a long time to provide aerated hollow spaces, also called interspaces, under the floors of residential and commercial buildings for the purposes of eliminating gases and humidity which can damage both people and the building structures.
A modern and rational solution to the problem of eliminating the humidity and gases is described in Italian patent specification 1,253,374 and in Italian design application no. PN93 0 000012, both of the present applicant. The solution of these documents is a modular element that is preferably molded out of a plastic material in the shape of a spherical cap. It is provided with four supports that are connected to each other by four arches. The side edges of the arches are shaped so as to enable contiguous elements to be joined to each other, due to respective edges being able to overlap and snap-fit together. The contiguous elements can then form a solid and continuous surface.
The prior art element described above, however, needs to be provided with reinforcing, i.e. stiffening ribs, in particular under the cap, so as to ensure that the surface is able to carry and withstand, without any problem, both the weight of the workers as the prior art element is installed, and the weight of the subsequent concrete casting. The prior art structural element is thus subject to both compressive and flexural stresses.
As a result, construction of the mold that is used to manufacture the prior art element is complicated, with a corresponding high cost. Furthermore, the prior art element itself, when made of molded plastic material, tends to be insufficiently resistant and unstable as a whole.